1. Field of the Invention
The invention relates to an X-Ray composition and an X-Ray sensitive element useful in a novel X-Ray recording process. An apparatus particularly suited to practicing the X-Ray recording process is also disclosed.
2. Description of Related Art
Most X-Ray recording processes that allow production of a permanent recording are based on photochemical reactions and require use of liquid chemical agents to develop and fix the image. This is the case in conventional silver-based processes in which silver halide is used as the X-Ray sensitive compound. Storage, handling and disposal of the required solutions entail safety precautions because of possible toxicity to humans and to the environment.
Other disadvantages are associated with liquid developers and fixers. As with any liquid, attention must be paid to containers, the need to be renewed at regular time intervals and, above all, protection of the immediate environment from spills and subsequent exposure.
There are X-Ray recording processes that do not use silver, namely processes that are based on xerography. However, these processes are considerably less sensitive than silver halide. Bulky equipment is required for development and the toners used may contain selenium and are quite toxic.
A nonsilver X-Ray recording process is described in U.S. Pat. No. 4,394,439. The process is based on the generation of free radicals resulting from photodegradation of certain polymeric materials exposed to X-Rays and a dye forming reaction initiated by the free radicals. Disadvantages of this process are low sensitivity and the requirement for chemical fixing.
U.S. Pat. No 4,699,872 also relates to a nonsilver recording process. This process is based on the sensitivity of choline chloride to high energy radiations, including X-Rays. Products of the photodissociation of choline chloride generate a dye which is responsible for the image. An undesirable feature of this process is the unpleasant odor generated during heat development of the image. An even more serious disadvantage is the lack of emulsion stability.
It can be seen that most of the existing processes for the recording of X-Ray images suffer from some disadvantage. Some of these are overcome by using nonconventional processes that do not employ silver solutions; however many nonsilver processes have low sensitivity, instability or unacceptable odor.